[Long-term opioid therapy in chronic noncancer pain. A systematic review and meta-analysis of efficacy, tolerability and safety in open-label extension trials with study duration of at least 26 weeks]

Immune response and cytokine profiles in post-laminectomy pain syndrome: comparative analysis after treatment with intrathecal opioids, oral opioids, and non-opioid therapies

INTRODUCTION

This study explores the interaction between cytokines, cell-mediated immunity (T cells, B cells, and NK cells), and prolonged morphine administration in chronic neuropathic pain patients without cancer-related issues. Despite evidence of opioid immunomodulation, few studies have compared these interactions.

METHODS

In a cross-sectional and comparative study, 50 patients with chronic low back radicular pain ("Failed Back Surgery Syndrome") were categorized into intrathecal morphine infusion (IT group, n = 18), oral morphine (PO group, n = 17), and non-opioid treatment (NO group, n = 15). Various parameters, including plasma and cerebrospinal fluid (CSF) cytokine concentrations, lymphocyte immunophenotyping, opioid escalation indices, cumulative morphine dose, and treatment duration, were assessed.

RESULTS

CSF IL-8 and IL-1β concentrations exceeded plasma levels in all patients. No differences in T, B, and NK lymphocyte numbers were observed between morphine-treated and non-treated patients. Higher plasma IL-5 and GM-CSF concentrations were noted in IT and PO groups compared to NO. CSF IFNγ concentrations were higher in PO and NO than IT. Positive correlations included CD4 concentrations with opioid escalation indices, and negative correlations involved NK cell concentrations, CSF TNFα concentrations, and opioid escalation indices. Positive correlations were identified between certain cytokines and pain intensity in IT patients, and between NK cells and cumulative morphine dose. Negative correlations were observed between CSF IL-5 concentrations and pain intensity in IT and PO, and between opioid escalation indices and CSF cytokine concentrations in PO and IT.

CONCLUSION

Associations between cytokines, cellular immunity, and prolonged morphine treatment, administered orally and intrathecally were identified.

Iatrogenic Side Effects of Pain Therapies

Pain regimens, particularly for chronic cancer and noncancer pain, must balance the important analgesic benefits against potential risks. Many effective and frequently used pain control regimens are associated with iatrogenic adverse events. Interventional procedures can be associated with nerve injuries, vascular injuries, trauma to the spinal cord, and epidural abscesses. Although rare, these adverse events are potentially catastrophic. Pharmacologic remedies for pain must also consider potential side effects that can occur even at therapeutic doses of over-the-counter remedies such as paracetamol (acetaminophen) or nonsteroidal anti-inflammatory drugs. Opioids are effective pain relievers but are associated with many side effects, some of which can be treatment limiting. A prevalent and distressing side effect of opioid therapy is constipation. Opioid-induced constipation is caused by binding to opioid receptors in the gastrointestinal system, making conventional laxatives ineffective. Peripherally acting mu-opioid receptor antagonists are a new drug class that offers the benefits of preserving opioid analgesia without side effects in the gastrointestinal system. An important safety concern, particularly among geriatric patients is the increasingly prevalent condition of polypharmacy. Many senior patients take five or more medications, including some that may be contraindicated in geriatric patients, duplicative of other drugs, have potential pharmacokinetic drug-drug interactions, or may not be the optimal choice for the patient's age and condition. Careful assessment of medications in the elderly, including possibly deprescribing with tapering of certain drugs, may be warranted but should be done systematically and under clinical supervision.

Feasibility study of a Behavioural Intervention for Opioid Reduction (BIOR) for patients with chronic non-cancer pain in primary care: a protocol

INTRODUCTION

Around 30%-50% of adults suffer moderate to severe chronic pain not caused by cancer. Significant numbers are treated with opioids which over time may cease to be effective and produce side effects (eg, nausea, drowsiness and constipation). Stopping taking opioids abruptly can cause unpleasant withdrawal effects. Tapering in small steps is recommended, though some patients might struggle and need support, particularly if they have limited access to pain management alternatives. Awareness of the potential risks as well as benefits of tapering should be explored with patients.

METHODS AND ANALYSIS

A randomised controlled pilot feasibility study to investigate the effectiveness and feasibility of reducing high doses of opioids through a tapering protocol, education and support in primary care. Working with NHS Knowsley Place, we will identify patients taking 50 mg or above morphine equivalent dose of opioids per day to be randomly allocated to either the tapering group or tapering with support group. At an initial joint appointment with a pain consultant and General Practitioner (GP) GP tapering will be discussed and negotiated. Both groups will have their opioid reduced by 10% per week. The taper with support group will have access to additional support, including motivational counselling, realistic goal setting and a toolkit of resources to promote self-management. Some patients will successfully reduce their dose each week. For others, this may be more difficult, and the tapering reduction will be adjusted to 10% per fortnight. We assess opioid use, pain and quality of life in both groups at the start and end of the study to determine which intervention works best to support people with chronic pain who wish to stop taking opioids.

ETHICS AND DISSEMINATION

The Behavioural Intervention for Opioid Reduction feasibility study has been granted full approval by Liverpool Central Research Ethics Committee on 7 April 2022 (22/NW/0047). The current protocol version is V.1.1, date 6 July 2022. Results will be published in peer-reviewed journals and disseminated to patient stakeholders in a lay summary report available on the project website and in participating GP surgeries.

TRIAL REGISTRATION NUMBER

ISRCTN 30201337.

Recent advances in the opioid mu receptor based pharmacotherapy for rheumatoid arthritis

INTRODUCTION

Opioids are used for severe forms of acute and cancer pain. Over the last years, their potential use in patients with noncancer pain such as those with rheumatoid arthritis (RA) has been postulated. A recent population-based comparative study showed that chronic opioid use was 12% vs. 4% among RA and non-RA patients, respectively. Another study showed an increase from 7.4% to 16.9% (2002 to 2015). In general, there has been an increasing tendency to use opioids in recent years.

AREAS COVERED

The authors have performed an extensive literature search using PubMed for articles including noncancer pain and the use of the mu opioid receptor (MOR) agonists in patients with RA.

EXPERT OPINION

Data is not sufficient to support opioid use for the treatment of chronic pain in patients with RA. Data is scarce and inconclusive. Rheumatologists should think and ponder the question: Why is this patient in pain? Differential diagnosis should include a disease flare, degenerative changes of the musculoskeletal system, and fibromyalgia. And while there are new strategies for opioid administration currently being researched, unfortunately, they are far from being applied to human subjects in the everyday clinical setting, and are still being evaluated at an experimental level. CNS: Central nervous system; DORs: delta opioid receptor agonists; GI: Gastrointestinal; GPCRs: G protein-coupled receptors; IL: Interleukin; JAK: Janus kinase; KORs: kappa opioid receptor agonists; MCPs: Metacarpophalangeal joints; MORs: Mu opioid receptor agonists; MTPs: Metatarsophalangeal joints; NSAIDs: Non-steroidal anti-inflammatory drugsOA: Osteoarthritis; ORs: Opioid receptors; PD: Pharmacodynamic; PIPs: Proximal interphalangeal joints; PK: Pharmacokinetic; PNS: Peripheral nervous system; RA: Rheumatoid arthritis; RGS: Regulator of G protein signaling; SSRIs: Selective serotonin reuptake inhibitors; TNF: Tumor necrosis factor.

Long-term opioid therapy for chronic noncancer pain: second update of the German guidelines

The opioid epidemic in North America challenges national guidelines worldwide to define the importance of opioids for the management of chronic noncancer pain (CNCP).

METHODS

The second update of the German guidelines on long-term opioid therapy for CNCP was developed by 26 scientific associations and 2 patient self-help organizations. A systematic literature search in CENTRAL, Medline, and Scopus (to May 2019) was performed. Meta-analyses of randomized controlled trials and open-label extension studies with opioids for CNCP were conducted. Levels of evidence were assigned according to the Oxford Centre for Evidence-Based Medicine classification system. The formulation and strength of recommendations were established by multistep formalized procedures to reach a consensus according to German Association of the Medical Scientific Societies regulations. The guidelines underwent external review by 4 experts and public commentary.

RESULTS

Opioids are one drug-based treatment option for short- (4-12 weeks), intermediate- (13-26 weeks), and long-term (>26 weeks) therapy of chronic pain in osteoarthritis, diabetic polyneuropathy, postherpetic neuralgia, and low back pain. Contraindications are primary headaches, functional somatic syndromes, and mental disorders with the (cardinal) symptom of pain. For specified other clinical pain conditions, short- and long-term therapy with opioids should be evaluated on an individual basis. Long-term therapy with opioids is associated with relevant risks.

CONCLUSION

Responsible application of opioids requires consideration of possible indications and contraindications, as well as regular assessment of clinical response and adverse effects. Neither uncritical opioid prescription nor general rejection of opioids is justified in patients with CNCP.

[Method report of the second update of the guidelines on long-term opioid therapy for chronic noncancer pain]

BACKGROUND

The update of the German S3 guidelines on long-term opioid therapy of chronic noncancer pain (CNCP), the LONTS (AWMF registration number 145/003), was scheduled for February 2020 due to the expiry of the validity period.

METHODS

The guidelines were updated by 28 scientific societies and 2 patient self-help organizations under the coordination of the German Pain Society and the Association of the Scientific Medical Societies in Germany (AWMF).

RESULTS

A systematic literature search was performed in the CENTRAL, MEDLINE and Scopus databases from October 2013 to December 2018. The previous meta-analyses of randomized controlled trials (RCT) of opioids in CNPC syndromes with a study duration of ≥4 weeks were updated. Levels of evidence were assigned according to the Oxford Centre for Evidence-Based Medicine version 2009 classification system. The formulation and strength of recommendations was established in a multistep formalized consensus procedure, in accordance with AWMF rules and standards. The guidelines were reviewed by four experts not involved in the development of the guidelines. The public was given the opportunity to comment on the guidelines. The guidelines were approved by the executive boards of the societies that were engaged in development of the guidelines.

CONCLUSION

The guidelines will be published in several forms: complete and short scientific versions as well as clinical practice and patient versions.

Analgesic Use in Patients With Advanced Chronic Kidney Disease: A Systematic Review and Meta-Analysis

Background:

Pain is common in patients with chronic kidney disease (CKD). Analgesics may be appropriate for some CKD patients.

Objectives:

To determine the prevalence of overall analgesic use and the use of different types of analgesics including acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), adjuvants, and opioids in patients with CKD.

Design:

Systematic review and meta-analysis.

Setting:

Interventional and observational studies presenting data from 2000 or later. Exclusion criteria included acute kidney injury or studies that limited the study population to a specific cause, symptom, and/or comorbidity.

Patients:

Adults with stage 3-5 CKD including dialysis patients and those managed conservatively without dialysis.

Measurements:

Data extracted included title, first author, design, country, year of data collection, publication year, mean age, stage of CKD, prevalence of analgesic use, and the types of analgesics prescribed.

Methods:

Databases searched included MEDLINE, CINAHL, EMBASE, and Cochrane Library. Two reviewers independently screened all titles and abstracts, assessed potentially relevant articles, and extracted data. We estimated pooled prevalence of analgesic use and the I2 statistic was computed to measure heterogeneity. Random-effects models were used to account for variations in study design and sample populations, and a double arcsine transformation of the prevalence variables was used to accommodate potential overweighting of studies with very large or very small prevalence measurements. Sensitivity analyses were performed to determine the magnitude of publication bias and assess possible sources of heterogeneity.

Results:

Forty studies were included in the analysis. The prevalence of overall analgesic use in the random-effects model was 50.8%. The prevalence of acetaminophen, NSAIDs, and adjuvant use was 27.5%, 17.2%, and 23.4%, respectively, while the prevalence of opioid use was 23.8%. Due to the possibility of publication bias, the actual prevalence of acetaminophen use in patients with advanced CKD may be substantially lower than this meta-analysis indicates. A trim-and-fill analysis decreased the pooled prevalence estimate of acetaminophen use to 5.4%. The prevalence rate for opioid use was highly influenced by 2 large US studies. When these were removed, the estimated prevalence decreased to 17.3%.

Limitations:

There was a lack of detailed information regarding the analgesic regimen (such as specific analgesics used within each class and inconsistent accounting for patients on multiple drugs and the use of over-the-counter analgesics such as acetaminophen and NSAIDs), patient characteristics, type of pain being treated, and the outcomes of treatment. Data on adjuvant use were very limited. These results, therefore, must be interpreted with caution.

Conclusions:

There was tremendous variability in the prescribing patterns of both nonopioid and opioid analgesics within and between countries suggesting widespread uncertainty about the optimal pharmacological approach to treating pain. Further research that incorporates robust reporting of analgesic regimens and links prescribing patterns to clinical outcomes is needed to guide optimal clinical practice.

Efficacy and harms of long-term opioid therapy in chronic non-cancer pain: Systematic review and meta-analysis of open-label extension trials with a study duration ≥26 weeks

BACKGROUND AND OBJECTIVE

This updated systematic review evaluated the efficacy, acceptability and safety of long-term opioid therapy (LTOT) for chronic non-cancer pain (CNCP).

DATABASES AND DATA TREATMENT

Clinicaltrials.gov, CENTRAL and MEDLINE until June 2019. We included open-label extension trials with a study duration ≥26 weeks of RCTs with ≥2 weeks duration. Pooled estimates of event rates of categorical data and standardized mean differences (SMD) of continuous variables were calculated using a random effects model.

RESULTS

We added four new studies with 1,154 participants for a total of 15 studies with 3,590 participants. Study duration ranged between 26 and 156 weeks. Studies included patients with low back, osteoarthritis and neuropathic pain. The quality of evidence for every outcome was very low. 31.1% (95% Confidence interval [CI] 23.0%-40.7%) of patients randomized at baseline finished the open label period. 14.1% (95% CI 10.9%-19.4%) of patients dropped out to due adverse events. In 6.3% (95 CI 3.9%-10.1%) of patients serious adverse events and in 2.7% (95% CI 1.5%-4.7%) aberrant drug behaviour were noted. 0.5% (95% CI 0.2%-1.4%) of patients died.

CONCLUSIONS

Within the context of open-label extension studies, opioids maintain reduction of pain and disability and are rather well tolerated and safe. LTOT can be considered in carefully selected and monitored patients with low back, osteoarthritis and neuropathic pain who experience a clinically meaningful pain reduction with at least tolerable adverse events in short-term opioid therapy.

SIGNIFICANCE

There is very low quality evidence of the long-term efficacy, tolerability and safety of opioids for chronic low back, osteoarthritis and diabetic polyneuropathic pain within the context of open-label extension studies of randomized controlled trials. Drop out rate due to adverse events and deaths increase with study duration. One-third of patients profit from LTOT. Long-term opioid therapy can be considered in some carefully selected and monitored patients.

The prescription opioid conundrum: 21st century solutions to a millennia-long problem

Health-care professionals are faced with a daunting task: balancing appropriate care for chronic pain with their responsibility to keep patients and others safe from treatment-related harm. Whereas opioids have historically been considered an effective tool in the analgesic armamentarium, the rise of opioid abuse has caused the pendulum to swing away from prescribing opioids to an emphasis on safety. This paradigm shift risks neglecting the very real consequences of untreated/undertreated pain. Using data from the medical literature, this review examines influences on the real and perceived benefit-to-risk ratio for opioids and provides clinicians with a practical approach to prescribing opioids that minimizes the risk for abuse/misuse. There is appreciable clinical trial and observational evidence of efficacy/effectiveness with opioids used for pain management over the short or long term when considered in the context of pharmacologic alternatives. Enhancing the relative safety and minimizing the risk for abuse/misuse may be achieved through proactive prescription practices that include careful patient selection, risk assessment, individualized and multimodal treatment plans with established goals, initiating opioid treatment cautiously with an exit plan in place, ongoing assessments of response to therapy, and routine patient monitoring. Additionally, prescribing opioids with a lower potential for abuse or misuse (e.g. abuse-deterrent formulations) may provide a benefit. Using a pragmatic approach to prescribing practices, we postulate that the balance between benefit and risk can be favorable for opioid therapy in select patients, even for long-term treatment of chronic pain.

Opioid-induced constipation: a narrative review of therapeutic options in clinical management

Pain therapy often entails gastrointestinal adverse events. While opioids are effective drugs for pain relief, the incidence of opioid-induced constipation (OIC) varies greatly from 15% to as high as 81%. This can lead to a significant impairment in quality of life, often resulting in discontinuation of opioid therapy. In this regard, a good doctor-patient relationship is especially pivotal when initiating opioid therapy. In addition to a detailed history of bowel habits, patient education regarding the possible gastrointestinal side effects of the drugs is crucial. In addition, the bowel function must be regularly evaluated for the entire duration of treatment with opioids. Furthermore, if the patient has preexisting constipation that is well under control, continuation of that treatment is important. In the absence of such history, general recommendations should include sufficient fluid intake, physical activity, and regular intake of dietary fiber. In patients of OIC with ongoing opioid therapy, the necessity of opioid use should be critically reevaluated in terms of an with acceptable quality of life, particularly in cases of non-cancer pain. If opioids must be continued, lowering the dose may help, as well as changing the type of opioid. If these measures do not suffice, the next step for persistent OIC is the administration of laxatives. If these are ineffective as well, treatment with peripherally active μ-opioid receptor antagonists should be considered. Enemas and irrigation are emergency measures, often used as a last resort.

Efficacy of opioids versus placebo in chronic pain: a systematic review and meta-analysis of enriched enrollment randomized withdrawal trials

Introduction

Opioids have been used for millennia for the treatment of pain. However, the long-term efficacy of opioids to treat chronic non-cancer pain continues to be debated. To evaluate opioids’ efficacy in chronic non-cancer pain, we performed a meta-analysis of published clinical trials for μ-opioid receptor agonists performed for US Food and Drug Administration approval.

Methods

MEDLINE and Cochrane trial register were searched for enriched enrollment randomized withdrawal studies (before June 2016). Selection criteria included: adults, ≥10 subjects per arm, any chronic pain condition, double-blind treatment period lasting ≥12 weeks, and all μ-agonist opioids approved in the USA.

Results

Fifteen studies met criteria. Opioid efficacy was statistically significant (p<0.001) versus placebo for pain intensity (standardized mean difference: −0.416), ≥30% and ≥50% improvement in pain (risk difference: 0.166 and 0.137), patient global impression of change (0.163), and patient global assessment of study medication (0.194). There were minor benefits on physical function and no effect on mental function.

Conclusion

Opioids are efficacious in the treatment of chronic non-cancer pain for up to 3 months in randomized controlled trials. This should be considered, alongside data on opioid safety, in the use of opioids for the treatment of chronic pain.

Non-Specific Low Back Pain

BACKGROUND

For many years, low back pain has been both the leading cause of days lost from work and the leading indication for medical rehabilitation. The goal of the German Disease Management Guideline (NDMG) on nonspecific low back pain is to improve the treatment of patients with this condition.

METHODS

The current update of the NDMG on non-specific low back pain is based on articles retrieved by a systematic search of the literature for systematic reviews. Its recommendations for diagnosis and treatment were developed by a collaborative effort of 29 scientific medical societies and organizations and approved in a formal consensus process.

RESULTS

If the history and physical examination do not arouse any suspicion of a dangerous underlying cause, no further diagnostic evaluation is indicated for the time being. Passive, reactive measures should be taken only in combination with activating measures, or not at all. When drugs are used for symptomatic treatment, patients should be treated with the most suitable drug in the lowest possible dose and for as short a time as possible.

CONCLUSION

A physician should be in charge of the overall care process. The patient should be kept well informed over the entire course of his or her illness and should be encouraged to adopt a healthful lifestyle, including regular physical exercise.

The opioid epidemic and national guidelines for opioid therapy for chronic noncancer pain: a perspective from different continents

INTRODUCTION

A marked rise in opioid prescriptions for patients with chronic noncancer pain (CNCP) with a parallel increase in opioid abuse/misuse, and resulting deaths was noted in the Unites states in the past decade (opioid epidemic). In response, the US Center of Diseases Control (CDC) developed a guideline for prescribing of opioids for patients with CNCP.

OBJECTIVES

To assess (1) if there is an opioid epidemic in Australia, Canada, and Germany (2) to compare Australian, Canadian, German, and Center of Diseases Control guidelines recommendations for long-term opioid therapy for CNCP.

METHODS

National evidence-based guidelines and PubMed were searched for recommendations for opioid prescriptions for CNCP.

RESULTS

There are signs of an opioid epidemic in Australia and Canada, but not in Germany. Guidelines in all 4 countries provide similar recommendations: opioids are not the first-line therapy for patients with CNCP; regular clinical assessments of benefits and harms are necessary; excessive doses should be avoided (recommended morphine equivalent daily doses range from 50 to 200 mg/d); stopping rules should be followed. All guidelines do not recommend the use of opioids in chronic pain conditions without an established nociceptive or neuropathic cause such as fibromyalgia and primary headache.

CONCLUSION

Implementation of opioid prescribing guidelines should ensure that physicians prescribe opioids only for appropriate indications in limited doses for selected patients and advice patients on their safe use. These measures could contribute to reduce prescription opioid misuse/abuse and deaths.

[Opioids for noncancer pain in the elderly]

BACKGROUND

Opioids are increasingly used in the elderly. Side effects differ compared to other analgesics.

PURPOSE

In this review article, special aspects about using opioids for noncancer pain in older people and in geriatric patients are identified.

CURRENT SITUATION

So far randomized controlled trials for the indication of and comparison between various opioids have been performed in middle-aged patients and not exclusively in geriatric patients or elderly (> 75 years). Furthermore, the evidence for multimorbid elderly patients with respect to side effects is also very poor.

RECOMMENDATIONS

The indication for opioid therapy should be narrow. The patient and their caregivers must be provided patient information regarding opioid therapy. The principle "start low, go slow" is highly recommended. To reduce the risk of falls, longer acting opioids should be used and short acting opioids should be avoided. Everyday relevant negative effects on cognition are possible in opioid use and have to be observed. As recommended in the recently published German guideline for long-term use of opioids in noncancer pain a critical check after 3 months and in case of dosing over 120 mg morphine equivalents is advisable, especially for older patients. Liver and kidney function and drug interactions have to be taken into consideration like in every age group.

[S3 guidelines on long-term opioid treatment in non-cancer pain. Recommendations for opioid use in clinical rheumatology]

The long-term use of opioids for chronic pain can be problematic in many respects. Besides potentially harmful and considerable undesired side effects and possible drug abuse, the indications for prescription, efficacy and safety in the long run have to be considered. The recently updated S3 guidelines on long-term opioid treatment in non-cancer pain (LONTS) provide recommendations with the highest currently available evidence. This article summarizes the most relevant contents for the clinical rheumatologist.

[Opioids in chronic low back pain. A systematic review and meta-analysis of efficacy, tolerability and safety in randomized placebo-controlled studies of at least 4 weeks duration]

BACKGROUND

The efficacy and safety of opioid therapy in chronic low back pain (CLBP) is under debate. We updated a recent systematic review on the efficacy and safety of opioids in CLBP.

METHODS

We screened MEDLINE, Scopus and the Cochrane Central Register of Controlled Trials (CENTRAL) up until October 2013, as well as reference sections of original studies and systematic reviews of randomized controlled trials (RCTs) of opioids in CLBP. We included double-blind randomized placebo-controlled studies of at least 4 weeks duration. Using a random effects model, absolute risk differences (RD) were calculated for categorical data and standardized mean differences (SMD) for continuous variables.

RESULTS

We included 12 RCTs with 17 treatment arms and 4375 participants. Median study duration was 12 (4-16) weeks. Of the 17 treatment arms, seven (41.2 %) used oxycodone; four (23.6 %) tramadol; buprenorphine and oxymorphone were each used in two (11.8 %) and hydromorphone and tapentadol each in one (5.8 %). The results for studies with parallel/cross-over design were as follows (with 95 % confidence interval, CI): opioids were superior to placebo in reducing pain intensity (SMD - 0.29 [- 0.37, - 0.21], p < 0.0001; six studies with 2896 participants). Opioids were superior to placebo in 50 % pain reduction (RD 0.05 [0.01, 0.10], p = 0.01; two studies with 1492 participants; number needed to benefit (NNTB) 19 [95 % CI 10-107]). Opioids were not superior to placebo in reports of much or very much improved pain (RD 0.16 [- 0.01, 0.34], p = 0.07; two studies with 1153 participants). Opioids were superior to placebo in improving physical functioning (SMD - 0.22 [- 0.31, - 0.12], p < 0.0001; four studies with 1895 participants). Patients dropped out less frequently with opioids than with placebo due to lack of efficacy (RD - 0.10 [- 0.16, - 0.04], p = 0.001; five studies with 3168 participants; NNTB 10 [8-13]). Patients dropped out more frequently with opioids than with placebo due to adverse events (RD 0.12 [0.05, 0.19], p = 0.0007; six studies with 2910 participants; number needed to harm (NNTH) 7 [95 % CI 6-8]). There was no significant difference between opioids and placebo in terms of the frequency of serious adverse events or deaths.

CONCLUSION

Opioids were superior to placebo in terms of efficacy and inferior in terms of tolerability. Opioids and placebo did not differ in terms of safety during the study period. The conclusion on the safety of opioids compared to placebo is limited by the low number of serious adverse events and deaths. Short-term and intermediate-term opioid therapy may be considered in selected CLBP patients. The English full-text version of this article is freely available at SpringerLink (under "Supplemental").

[Methodology of the development of the updated LONTS guidelines for long-term administration of opioids in noncancer pain]

BACKGROUND

The update of the German S3 guidelines on long-term opioid therapy of chronic noncancer pain (CNCP), the"LONTS" (AWMF registration number 145/003) was scheduled for May 2014.

METHODS

The guidelines were developed by 25 scientific societies and two patient self-help organizations under the coordination of the German Pain Society and the Association of the Scientific Medical Societies in Germany (AWMF).

RESULTS

A systematic literature search was performed in the CENTRAL, MEDLINE and Scopus databases from October 2008 to October 2013. Meta-analyses of randomized controlled trials (RCT) of opioids in CNPC of study duration ≥ 4 weeks were conducted. Levels of evidence were assigned according to the Oxford Centre for Evidence-Based Medicine version 2009 classification system. The formulation and strength of recommendations was established in a multistep formalized consensus procedure, in accordance with AWFM rules and standards. The guidelines were reviewed by three scientific societies not involved in their development and were approved by the executive boards of the societies that were engaged in development of the guidelines.

CONCLUSION

The guidelines will be published in several forms: complete and short scientific versions, as well as clinical practice and patient versions.

[Recommendations of the updated LONTS guidelines. Long-term opioid therapy for chronic noncancer pain]

BACKGROUND

The regular update of the German S3 guidelines on long-term opioid therapy for chronic noncancer pain (CNCP), the"LONTS" (AWMF registration number 145/003), began in November 2013.

METHODS

The guidelines were developed by 26 scientific societies and two patient self-help organisations under the coordination of the Deutsche Schmerzgesellschaft (German Pain Society). A systematic literature search in the Cochrane Central Register of Controlled Trials (CENTRAL), Medline and Scopus databases (up until October 2013) was performed. Levels of evidence were assigned according to the classification system of the Oxford Centre for Evidence-Based Medicine. The strength of the recommendations was established by multistep formal procedures, in order to reach a consensus according to German Association of the Medical Scientific Societies ("Arbeitsgemeinschaft der Wissenschaftlich Medizinischen Fachgesellschaften", AWMF) regulations. The guidelines were reviewed by the Drug Commission of the German Medical Association, the Austrian Pain Society and the Swiss Association for the Study of Pain.

RESULTS

Opioids are one drug-based treatment option for short- (4-12 weeks), intermediate- (13-25 weeks) and long-term (≥ 26 weeks) therapy of chronic osteoarthritis, diabetic polyneuropathy, postherpetic neuralgia and low back pain. Contraindications are primary headaches, as well as functional somatic syndromes and mental disorders with the (cardinal) symptom pain. For all other clinical presentations, a short- and long-term therapy with opioid-containing analgesics should be evaluated on an individual basis. Long-term therapy with opioid-containing analgesics is associated with relevant risks (sexual disorders, increased mortality).

CONCLUSION

Responsible application of opioid-containing analgesics requires consideration of possible indications and contraindications, as well as regular assessment of efficacy and adverse effects. Neither an uncritical increase in opioid application, nor the global rejection of opioid-containing analgesics is justified in patients with CNCP.

Oxycodone for pain in fibromyalgia in adults

BACKGROUND

This review replaces part of an earlier review that evaluated oxycodone for both neuropathic pain and fibromyalgia, which has now been split into separate reviews for the two conditions. This review will consider pain in fibromyalgia only.Opioid drugs are commonly used to treat fibromyalgia, but they may not be beneficial for people with this condition. Most reviews have examined all opioids together. This review sought evidence specifically for oxycodone, at any dose, and by any route of administration.

OBJECTIVES

To assess the analgesic efficacy and adverse events of oxycodone for treating pain in fibromyalgia in adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE for randomised controlled trials from inception to 25 July 2016. We also searched the reference lists of retrieved studies and reviews, and searched online clinical trial registries.

SELECTION CRITERIA

We planned to include randomised, double-blind trials of eight weeks' duration or longer, comparing oxycodone (alone or in fixed-dose combination with naloxone) with placebo or another active treatment. We did not include observational studies.

DATA COLLECTION AND ANALYSIS

The plan was for two independent review authors to extract data and assess trial quality and potential bias. Where pooled analysis was possible, we planned to use dichotomous data to calculate risk ratio and numbers needed to treat for one additional event, using standard methods.

MAIN RESULTS

No study satisfied the inclusion criteria. Effects of interventions were not assessed as there were no included studies. We have only very low quality evidence and are very uncertain about estimates of benefit and harm.

AUTHORS' CONCLUSIONS

There is no randomised trial evidence to support or refute the suggestion that oxycodone, alone or in combination with naloxone, reduces pain in fibromyalgia.

The opioid epidemic and the long-term opioid therapy for chronic noncancer pain revisited: a transatlantic perspective

The rise of opioid prescriptions and associated deaths ('opioid epidemic') in North America has evoked worldwide discussions on the long-term efficacy and safety of long-term opioid therapy (LtOT) for chronic noncancer pain (CNCP). We discuss if the opioid epidemic is a real worldwide or a more North American phenomenon. We consider reasons of the opioid epidemic. We highlight differences in the appraisal of the evidence of recent systematic reviews on LtOT for CNCP of US and European authors. We discuss similarities and differences of recent North American and European guidelines on LtOT for chronic CNCP. We point out potential indications and contraindications of LtOT in CNCP syndromes.

Meta-analyses of pain studies: What we have learned

Meta-analysis is a statistical procedure that integrates the results of at least two independent studies. The biggest threats to meta-analysis are publication bias due to missing studies with negative results and low-quality evidence due to methodological limitations imposed by included studies. Tools to improve the quality of meta-analysis have been developed by the Cochrane Collaboration and by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Meta-analyses of trials have demonstrated that pain responses in patients with chronic pain, following treatment, are not normally distributed but have a bimodal distribution with the majority of patients having either very little or very good pain relief. The benefit can be detected within 2-4 weeks following drug administration. Further, the efficacy of drug and physical treatments is hampered by high placebo response rates, with modest average benefits with active treatments over placebo in both parallel and crossover design trials.

Long-term opioid use in non-cancer pain

BACKGROUND

The long-term use of opioid analgesic drugs to treat chronic non-cancer pain (CNCP) is a major component of pain pharmacotherapy. The interpretation of the evidence concerning its efficacy and risks is currently debated.

METHODS

An interdisciplinary evidence- and consensus-based S3 guideline was updated on the basis of a systematic literature search (CENTRAL, Medline, and Scopus databases, from October 2008 to October 2013); meta-analyses of randomized controlled trials (≥ 4 weeks); and a consensus procedure, as specified by the AWMF regulations, including 22 medical and psychological societies and 2 patient self-help organizations.

RESULTS

119 publications were used to update the guideline, and 6 systematic reviews with meta-analyses were performed. A nominal group process was used to formulate recommendations concerning the indications and contraindications for the treatment of CNCP with opioid analgesics and the manner in which such treatments should be carried out. Opioid analgesics are an option for the short-term treatment (4-12 weeks) of chronic pain due to osteoarthritis (pain intensity, standardized mean difference [SMD]: -0.22 and -0.26), diabetic polyneuropathy (SMD -0.74), post-herpetic neuralgia (SMD -0.58), and chronic low back pain (SMD: -0.29 and -0.74). Long-term opioid treatment (≥ 26 weeks) for these diseases benefits only about 25% of patients. For other conditions, either short- or long-term treatment with opioid analgesics should be considered an individual therapeutic trial. Opioid treatment for pain is contraindicated by primary headaches and by any functional or mental disorder of which pain is a leading manifestation.

CONCLUSION

To minimize the risks of opioid analgesic treatment, physicians must be aware of its contraindications and must regularly reassess its efficacy and side effects. Pharmacotherapy should be combined with other types of treatment.